There have been many problems associated with developing hard surface coatings that provide a beneficial layer with the desirable properties and which minimize the disadvantages, such as a limit to single use protection, insufficient coverage, roughness and/or flaking of coating during use, or in contrast, the inability to remove once applied (when a more temporary coating is desired), a limit on surfaces that can be modified, photoactive damage and degradation of the surface.
The current approach to solving the coating problem is with the use of surfactants, film-forming polymer coatings, clay-containing-film-forming polymer coatings and photoactive inorganic metal oxide coatings. However, the substantivity of the film-forming polymers (e.g. alkoxylated silicones, poly(N-vinyl-2-pyrrolidones, poly(N-vinyl-imidazoles, diblock copolymers of poly(ethylene oxide) and poly(lactide)) is poor such that its wetting/sheeting effect is short-lived, with spotting/residue negatives returning within 1-2 rinses, exposures to the elements (e.g., rain, etc.), or conditions (e.g., water in a shower). Elevating the levels of polymers is not the solution to this problem. This is especially evident on automobile surfaces, residential windows, building exteriors, shower units and dishware where elevated levels of polymers result in unacceptable residue problem. In the case of clay-containing, film-forming polymer coatings, the nanoparticles are rheology agents for the formulations and do not themselves impart the benefit disclosed. One example of this approach is disclosed in U.S. Pat. No. 5,429,999, titled “Organoclay Compositions Containing Two Or More Cations And One Or More Organic Anions”, wherein preparation and use in non-aqueous systems of an organophilic clay gellant is used in a non-aqueous fluid system such as paints, inks, and coatings to provide improved rheological properties. Other related patents include: U.S. Pat. No. 5,785,749, titled “Method For Producing Rheological Additives And Coating Compositions Incorporating Same”; U.S. Pat. No. 5,780,376, titled “Organoclay Compositions”; U.S. Pat. No. 5,739,087, Titled “Organoclay Products Containing A Branched Chain Alkyl Quaternary Ammonium Ion”; U.S. Pat. No. 5,728,764, titled “Formulations Including Improved Organoclay Compositions”; and U.S. Pat. No. 6,036,765, titled “Organoclay Compositions And Method Of Preparation”.
Another approach to this problem is disclosed in U.S. Pat. No. 4,597,886, titled “Dishwashing Compositions”, wherein an inclusion of an effective level of a layered clay (e.g. a synthetic hectorite) in an enzymatic dishwashing composition is introduced to reduce the formation of spots and films on the cleaned objects. U.S. Pat. No. 4,591,448, titled “Dishwashing Compositions”, discloses the use of a layered clay in a non-enzymatic dishwashing composition with a reduced pH of 9-11 to provide for a reduction of spot and film formation on the cleaned articles. See also U.S. Pat. No. 4,591,449. EP. Pat. No. 139,330 B1, titled “Rinse Aid” discloses the use of a layered clay as a rinse aid or rinse component for the aqueous rinsing step of a machine dishwashing process to provide anti-spotting benefits. In the abovementioned dishware care patents, the layered clay is introduced in the machine dishwashing detergent or rinse aide as a single-use application to prevent spotting and film formation during that particular wash cycle. These patents do not disclose a nanoparticle coating system requirement which is preventative in nature, unlike the present invention. Furthermore, they do not disclose multi-use benefits (such as, anti-spotting, anti-hazing, soil removal and minor surface defect repair) without additional treatment between uses.
The photoactive metal oxide approach using nanoparticles, such as zinc oxide (ZnO2) and titanium dioxide (TiO2), have serious limitations and harmful deleterious surface effects to overcome. The potential of using TiO2 to functionalize hard surfaces (1) is limited to surfaces exposed to outdoor levels of UV and (2) requires special surface safety precautions to protect against photoactivated damage mechanisms. In addition, TiO2 is difficult to apply to said surfaces and often requires professional treatment of the surface.
In the case of TiO2 thin films, an approach taken in JP. Pat. No. 11181339 A2, titled “Hydrophilic Coating Composition”, discloses a room-temperature-settable coating composition comprising an aqueous fluid containing photocatalytic titanium oxide particles having a particle diameter of 1-100 nm and tin oxide particles having a particle diameter of 1-100 nm and having a pH of 8-12 or a pH of 0-5, and a coating film which exhibits hydrophilicity when it is formed on a substrate and irradiated with ultraviolet rays at a wavelength of 200-400 nm and, and the photocatalytic titanium oxide is photoexcited. Other related patents disclosing methods and articles of use for the abovementioned titanium oxide coating composition include JP. Pat. No. 11172239 A2, titled “Hydrophilic Member, Method For Hydrophilization/Hydrophilicity Retention Of Surface Of Member, And Hydrophilic Coating Composition”; JP. Pat. No. 10297436 A2, titled “Manufacture Of Mirror For Vehicle With Improved Rainy Weather Visibility”; JP. Pat. No. 10046759 A2, titled “Roof Material Having Ice-Snow Sticking Preventive Performance, JP. Pat. No. 09056549 A2, titled “Anti-Fogging Mirror”; JP. Pat. No. 00128672 A2, titled “Ceramic Ware And Its Production”; JP. Pat. No. 00096800 A2, titled “Antifouling Building Material And Manufacture Thereof”; JP. Pat. No. 11300303 A2, titled “Cleaning Method Of Composite Material And Self-Cleaning Composite Material Mechanism”; JP. Pat. No. 10237431 A2, titled “Member With Ultrawater-Repellent Surface”; JP. Pat. No. 10212809 A2, titled “Building Material For External Wall”; JP. Pat. No. 09230107 A2, titled “Anti-Fogging Glass Lens And Its Anti-Fogging Method”; and JP. Pat. No. 09228072 A2, titled “Outdoor Member”. In the abovementioned patents, the hydrophilic TiO2 film can cause photo- and chemical-degradation of organic undercoats, and any rubber or plastic it comes into contact with, and requires professional means of application and treatment.
U.S. Pat. No. 4,164,509, titled “Process For Preparing Finely Divided Hydrophobic Oxide Particles” discloses a process for preparing hydrophobic finely divided particles of oxides of metals and/or oxides of silicon by chemically bonding hydrocarbon radicals to the surface of the oxide particles.
It is apparent that there is a continuing need in order to improve the various properties of all hard surfaces, including but not limited to fiberglass, plastics, metals, glass, ceramic, wood, stone, concrete, asphalt, mineral, and painted surfaces, via a coating composition, method of use and article of manufacture which would result in hard surfaces having one or more of the following highly desirable modified surface properties such as improved surface wetting and sheeting, quick drying, uniform drying, soil removal, self-cleaning, anti-spotting, anti-soil deposition, cleaner appearance, enhanced gloss, enhanced color, minor surface defect repair, improved smoothness, anti-hazing properties, modification of surface friction, release of actives, reduced damage to abrasion and improved transparency. There is also a continuing need that these modified surface benefits be made longer lasting than the approach made by the polymer patents or semi-permanent to be more responsive to consumer applications than the approach that utilizes photoactivated coatings alone (e.g. TiO2).
Nanoparticles have been used for a number of purposes in general coatings, but not for the abovementioned benefits. One example is disclosed in U.S. Pat. No. 4,173,480, titled “Photographic Sheet With Synthetic Hectorite Antistatic Additive As Sizing Or Backcoat”, wherein a polymer film base is coated with a synthetic hectorite clay, specifically Laponite S™. The binder is gelatin, starch or carboxy methylcellulose. The primary benefit here is to impart antistatic properties to the surface. In the present invention, the binder is not required to apply the nanoparticle to the surface.
Another example is disclosed in U.S. Pat. No. 4,868,048, titled “Conductive Sheet Material Having An Aqueous Conductive Composition, wherein certain fractions (i.e., neighborite) are removed from synthetic hectorite before use thereof as a coating with a non-epoxy binder. The primary benefit here is to impart conduction of electric charge to the surface. In the present invention, the binder is not required to apply the nanoparticle to the surface.
Another example is disclosed in JP. Pat. No. 8053558 A2, titled “Anti-Fog Synthetic Resin Film For Agriculture”, wherein colloidal alumina, colloidal silica, anionic surfactant, organic electrolyte and an inorganic layered compound form a film that exhibits sustained anti-fog properties at low- and high-temperatures. Another example is disclosed in JP. Pat. No. 04353438 A2, titled “Transparent Plastic Films With Good Dew And Blocking Preventing Effects”, discloses Li-Mg-Na silicate layers on 1 side of the films useful for greenhouses, book covers, card holders, etc. See also, EP 0732387 titled, “Antifogging agent composition and agricultural film coated therewith”.
Another example is disclosed in U.S. Pat. No. 4,786,558, titled “Composite Film And Antistatic Composite Film Comprising A Swellable Inorganic Silicate”, where the inorganic nanoparticle is modified by treating it with various ions to provide a composite film with antistatic benefits comprising a swellable inorganic silicate.
Another example is disclosed in W.O. Pat. 99/00457 Al, titled “Coating Agent For Reducing The Soiling Process Of Facades”, wherein the invention relates to the preparation of a system used for reducing the soiling process of building facades. Here the layered silicate is disclosed for its use as a gellant and is not responsible for the reduction of surface soiling benefits alone.
Another approach is disclosed in U.S. Pat. No. 5,853,809, entitled “Scratch Resistant Clearcoats Containing Surface Reactive Microparticles and Method Therefor” issued to Campbell, et al. This patent is directed to clearcoat coating compositions that, after application, comprise the outermost layer on automotive body panels. Reactive inorganic microparticles are added to the coating composition to improve scratch resistance.
Another approach taken is disclosed in U.S. Pat. No. 6,020,419, titled “Transparent Coating Compositions Containing Nanoscale Particles And Having Improved Scratch Resistance”, wherein specific combinations of properties in coatings, such as transparency and wear resistance, may be obtained by using nanoparticles.
The present invention relates to materials, coatings, compositions, methods, and articles of manufacture that provide some important hard surface multi-use benefits that can be made long lasting or semi-permanent. These multi-use benefits include at least one of the following: improved surface wetting and sheeting, quick drying, uniform drying, soil removal, self-cleaning, anti-spotting, anti-soil deposition, cleaner appearance, enhanced gloss, enhanced color, minor surface defect repair, improved smoothness, anti-hazing properties, modification of surface friction, release of actives, reduced damage to abrasion, and improved transparency (the latter in the case of surfaces such as glass and the like, particularly after such surfaces are soiled or contacted with water) relative to transparent surfaces that are not treated with the materials, coatings, or coating composition, and anti-fogging in the case of surfaces (such as mirrors) that are designed to reflect.